Maybe you have heard of ringworm, but beyond an idea that it's contagious, it's gross, and you hope you never get it, you may have a poor grasp of the actual facts. Dr. Karen Campbell, a board-certified veterinary dermatologist at the University of Illinois Veterinary Teaching Hospital in Urbana, dispels six common myths about ringworm.
1. Ringworm is caused by a worm.
This disease got its name because of the way it looks, not because it is caused by worms under the skin. Ringworm is caused by one of several common dermatophytes — fungi that grow on skin. The "ring" look comes when the skin heals in the center as the fungus spreads outwards.
2. You can't give ringworm to your pet or vice versa.
Actually, ringworm is quite contagious between mammals. Not only can you get it from your pet, you can just as easily give it to your pet, whether that is a cat, a dog, or even a rabbit. In fact, ringworm can affect any mammal.
3. Ringworm is only contagious through direct contact.
If that were true, the situation would be so much easier to resolve. The fungus infects the hairs, which are shed into the environment. These hairs can remain infectious for years. Part of treating a pet for ringworm involves extensive cleaning of the environment, that is, your house. Electrostatic wipes can be especially helpful for collecting all the pet hairs. Dr. Campbell recommends disinfecting all the surfaces you can with a common household cleaner. And don't forget the air vents!
4. Only the affected pet needs to be treated.
If one pet in a multi-pet household has ringworm, you need to worry about all the other pets too. If the animals spend time together, it is very possible that they all have ringworm even if they do not have any obvious sores. To address the situation, you can either have all animals tested, or just treat them all. The choice depends on your preference and cost. Testing takes time (days to weeks) and can be expensive. The most common treatment for ringworm is lime-sulfur dips, which are fairly inexpensive. Discuss which course of treatment is best for your situation with your veterinarian.
5. If there are no visible skin problems or hair loss, the animal does not have ringworm.
Some pets infected with ringworm may not show signs, but still carry the fungus, meaning they can still transmit the fungus to other animals or other people. Make sure if you have a pet with ringworm to follow through the whole course of treatment. Never stop treatment just because the animal looks better.
6. A circular area of hair loss on your pet means ringworm.
While ringworm can be missed or misdiagnosed (mistaken for something else), it is also over-diagnosed. A lot of things can cause your pet to itch and lose fur. Mites, fleas, bacterial infections, and even allergies can cause hairless patches that itch. Be sure to talk to your veterinarian. Treating for ringworm will not help if your dog is itchy because of mites.
Now that you are armed with the facts, you can do your best to avoid contracting ringworm—or to treat it aggressively if you or any member of your family does get it. If you still have questions about ringworm, your local veterinarian is an excellent source of information, so don't hesitate to ask.
An archive of Pet Columns from the University of Illinois College of Veterinary Medicine is available online at http://vetmed.illinois.edu/petcolumns/. Requests for reprints of this article may be directed to Chris Beuoy, email@example.com.
Veterinary Extension/Office of Public Engagement
University of Illinois College of Veterinary Medicine